1. Field of the Invention
The present invention relates to a construction machine such as a hydraulic excavator.
2. Description of the Related Art
In a conventional hydraulic excavator shown in FIG. 5, when a control box revolving lever 51 provided on the left hand at the lower part at the foot of a maneuvering seat 50 is pulled in a direction of arrow A, a control box 52 rotates in a direction of arrow B about a turning fulcrum 53. This facilitates up and down movement, and all the oil pressure is locked to prevent erroneous operation at the time of up and down movement.
In the construction machine provided with the jump-up control box 52 as described above, a plurality of pilot hoses 55 extending from a remote control valve 54 to a control valve are moved up and down with the jump-up operation. For the purpose of absorbing the up and down movement thereof, the pilot hoses 55 are positioned to the rear of the control box 52 and the turning fulcrum 53 is bypassed by the pilot hoses 55 which are substantially U-shaped.
In the pilot hose piping as described above, it is necessary that a plurality of hoses are forcibly pulled out rearward through an elbow 56 from the remote control valve 54 and moved around within the control box 52 while paying attention to an interference with other devices within the control box 52. Accordingly, there poses a problem in that it is difficult to install the pilot hoses 55 and it takes time to install them.
It is an object of the present invention to provide a construction machine for simplifying an installation of pilot hoses in case of being provided with a jump-up control box.
The construction machine according to the present invention comprises a maneuvering seat on which an operator sits, a guard cover for supporting the maneuvering seat thereon, a control box arranged on one side of the maneuvering seat, comprising a control valve and an operating lever for operating said control valve, and turning about a turning fulcrum so as to facilitate getting on to and off from the maneuvering seat for an operator, and hydraulic hoses which hang from said control valve and are pulled out of the control box, said hydraulic hoses having a bent portion externally of the control box, said bent portion being displaced when the control box turns to absorb up and down movement of the hydraulic hoses.
According to the above-described constitution, the up and down movement of the hydraulic hoses caused by jumping up of the control box is absorbed by the bent portion provided externally of the control box.
Further, according to the present invention, the hydraulic hoses may pass through forward of the turning fulcrum of the control box.
According to the above-described constitution, since the hydraulic hoses extending from the control valve are not necessary to bypass the turning fulcrum positioned at the rear of the control box as in prior art, installing of a hydraulic pipeline can be carried out in a short period of time and is simple.
Further, the present invention may further comprise a duct provided internally of the guard cover, which receives the hydraulic hoses with a play, and an L-shaped bent portion formed in the duct for maintaining the shape of said bent portion of the hydraulic hoses.
According to the above-described constitution, the hydraulic hoses are received within the duct having an L-shaped bent portion with a play, this protecting the hydraulic hoses. The duct holds the bent shape of the hydraulic hoses when the control box is in a normal position, and displaces the hydraulic hoses within the duct to absorb the up and down movement thereof when the control box is jumped up.
Further, according to the present invention, the duct may be mounted so as to be along the front surface of the guard cover positioned below the maneuvering seat.
According to the above-described constitution, since it is designed so that the duct may be mounted parallel with the front surface of the guard cover, there is no possible interference with other devices within the guard cover, and the installing work of the hydraulic hoses can be carried out simply.
Further, the front surface of the guard cover may be detachable. In this case, the maintenance of the hydraulic hoses or the like can be carried out easily,
The duct is molded into a U-shape, and the hydraulic hoses extended from the other side of the maneuvering seat may be received into the duct. Further, the hydraulic hoses on one side and the hydraulic hoses on the other side may be gathered in the center of the duct, and pulled out of an opening formed in the central portion at the lower part of the duct.
Further, it may be also designed that a top plate of the guard cover is turned forward and opened with a front edge portion of the guard cover being a fulcrum, and also when the top plate turns, the bent portion is displaced to absorb the up and down movement of the hydraulic hoses.